Iphone Not Broadcasting Audio

Hello, Just purchased the Stick Up Cam Solar and installed yesterday. My phone when in live video mode will broadcast my voice and I can hear the sounds off the mic of the camera back onto my phone. But my fiance's iphone will not broadcast her voice to the speaker on the camera. But you can hear the sounds off of the mic on the camera to her phone. The camera is currently updated and I have allowed acces to the mic on her Iphone. Nothing is working.How do I resolve this?